实现简化版的JSON.stringify

 1 JSON.stringify
 2 var o={"a":1,"b":2,"c":"cc","d":{"aaa":1,"bbb":"2"}};
 3 function o2s(o){
 4  var s=[‘{‘];
 5  for(var k in o){
 6  s.push(‘"‘+k+‘":‘);
 7  if(typeof o[k] ==‘number‘){
 8  s.push(o[k]);
 9  }else if(typeof o[k]==‘object‘){
10  s.push(o2s(o[k]));
11  }else{
12  s.push(‘"‘+o[k]+‘"‘);
13  }
14  s.push(‘,‘);
15  }
16  s.pop();
17  s.push(‘}‘);
18  return s.join(‘‘);
19 }
20 var s=o2s(o);
21 console.log(JSON.parse(s));
22 alert(o);